Chart or means for reading signals.



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A. J. MUNDY.

UNITED STATES PATENT OFFICE.

ARTHUR J. MUNDY, OF OSTON, MASSACHUSETTS, ASSIGNOR TO TIIE GRAY r[ ELEPHONE COMPANY OF VVATERVILL'S, MAINE, OF SAME PLACE.

CHART OR MEANS FOR READING SIGNALS.

SPECIFICATION forming part of Letters Patent No. 667,137, dated January 29, 1901. Application filed November 1| 1900. Serial No. 35,092. (No model.)

To all whom, it may concern,.-

Be it known that I, ARTHUR J. MUNDY, a citizen of the United States, residing at Boston, in the county of Suffolk and State of Mas- 5 sachusetts, have invented a new and useful Improvement in Charts or Means for Reading Signals, of which the following is a full, clear, and exact description, reference being had to .the accompanying drawings, forming 1o a part of this specification, in explaining its nature.

The invention relates to a chart or means for reading signals adapted to be employed in connection with the method of signaling I 5 described and claimed in my application for Letters Patent of the United States, filed May 25, 1900, Serial No. 18,016. In said application I have described a method of signaling useful in any medium, but therein especially zo described as applicable to submarine signaling. It is produced by submerging soundproducing devices at known distances from each other and preferably in a triangular relation to each other and actuating them in 2 5 any convenient or desirable way, preferably from a sound-actuating station more or less remote .from the signals. Any suitable soundmaking devices may be used, and I have mentioned among them the apparatus described in the patent to Elisha Gray and myself,dated November 7, 1899, No. 636,519, although I would not be untlerstood as conning myself to any particular form of sound-producing device or to their number or to the means of 35 actuating them. The signals may be sounded simultaneously or they may be sounded successively and they may be diierentiated from each other in any desired Way-that is, one

, signal may be indicated by a single sound impulse, the second by two sound impulses, and the third by three souudimpulses', or the first may have a tone of a given pitch, the second a. tone of another pitch, and the third a tone of a third pitch.

` 4; It is desirable and even essential when three signal-stations triangularly arranged are used in practicing the method that the distances between the signal-stations be known and that the difference in the timeof their operation 5o Where they are operated successively be also known. With these determinate factors and with the knowledge of the number of feet por second sound travels it is then possible for an observer Within the area in which said sounds are audible to locate his position in 55 respect to the fixed signaling-points, for it then becomes a matt-er of computation based upon the distances between the signals, the rate at which sounds travel, and the interval between the times when the sounds of the 6o different signals reach the observer. Sound travels in water from the signaling-point at the rate of four thousand seven hundred andtwelve feet per second and in the air at. the rate of eleven hundred feet per second. The 65 sounds from each signal radiate in all directions and travel with equal speed, and this fact enables the method to be carried into effect and applied by means of the chart represented in the drawings which forma part 7o of this specification.-

In the drawings, Figure 1 represents a chart which is used in conjunction with a triangular arrangelnent of signaling points. Fig. 2 represents a modified form of the chart 75 useful where two signaling-points are employed.

In Fig. 1, A represents `one signaling point or station, B the second signaling point or station, and C the third signaling point or 8o station. They are' representedlas ydisposed with respect to each other at the points or apexes of a equilateral triangle and are assumed to be separated from each other by a distance of about four miles. If an observer 85 were to be located in the center of the diagram which the chart represents and the three signals A, B, and C were to be simultaneously actuated, he would hear the three signals at the same instant. If, however, the position 9o of the observer were shifted so as to move along a line drawn between the center of the triangle and one of the signaling-points and the three 'signals were again sounded simultaneously, the .observer would hear the near- 9 5 est signal before he heard the two others, which would then immediately sound simultaneously, the latter two signals still being equally distant from the new position of the observer. If the observer again change his loo position by moving either to the right or to the left of the said line, so that all three signals are at different distances from him, and again the three signals are sounded simultaneously,he will then heal-them successively at intervals which bear a direct relation to the distances separating him from each of them. If the signals are sounded in successive order, then the time between the intervals of their sounding becomes an element for consideration, and the chart or diagram of Fig. l of the drawings represents an arrangement in which the signals are sounded successively at regular `intervals of ten seconds between each, the three signals sounding in a cycle of thirty seconds. vThe times at which the signals thus sounded will reach given distances from the signals are indicated upon the chart by the curved lines d, a few of which only are lettered, and also by the three straight lines a, b, and c. These curved and straight lines are arranged with respect to the centers A, B, and C, as indicated in Fig. l, and intersect.- The points of intersection represent definite distances from and angles with respect to the three signal-stations. By means of sounds received from the signals the observer is enabled to'ascertain upon the chart his position with regard to the signaling-stations, each ofthe curved lines upon the chart having at itsend or, if desired, otherwise located upon it a designating-number which indicates its value in m aking this determination.v For instance,supp'ose the observer should ascertain that the interval of time between the signals received from point A and point B should be eight and onehalf seconds, that the interval of time between signals received from point B and point C should be ten and one-half seconds, andthat the interval of time between signals received from point C and lpoint A should be eleven seconds he would then find upon the chart the intersecting point of the curved lines numbered 85, 10%,77 and 11,which is represented upon the chart by a circle, and

'he would thus ascertain his relation bothV as to distances and as to angles of direction with respect to the three signaling-points A, B, and C. When the three signals are actuated successively at intervals of ten seconds, the sum of theY intervals of time between the sounding of the three signals and the time when received by the observer should always be thirty-that is, upon the supposition that he accurately notes the time between the soundings as they vreach him.

The signaling-points A, B, and C of Fig. 1 are separated from each other in time by'intervals of iiv'e seconds or twenty-three thousand ve hundred and sixty feet.

In Fig. 2 I have represented a modified form of chart in which two signaling-points are shown, and with this modification the ob server may readily find his position between the two signals and aline along which he may move. The curved solid lines in this figure represent the lines of progress of the'sound in radiating from the signal-points, and the numbering of these lines represents the time taken by the sound in radiating from-the signal-points to the lines. The numbering of the dotted lines of the ligure shows the time intervals between the signals as they reach the observer, provided signal B is sounded ten seconds aftersignal A. The n umberiugof these dotted lines contained in circles shows the time intervals between the signals as they reach the observer, provided the signals are sounded simultaneously. When the two signals are sounded simultaneously, their identitymust be determined by pitch or dierence in character of the sounds, as the sounding of numbered signals'would then create confusion. terval of time between the' sounding of the signals is allowed, numbered signals are preferable.

I have said that the diagram Fig. l represents the signals as separated by twenty-three thousand five hundred and sixtyfeet. This is upon the supposition that they are submerged and that the sounds are communi.

cated by water. It not submerged or in the air, the diagram would lthen represent signals separated by a distance ot five thousand five hundred feet.

In Fig. 2 the indicating-figures against the ends of the lines on the chart which are not inclosed by a circular border form a part of a diagram in which each signal is sounded at intervals of ten seconds, so that signal B is sounded ten seconds after signal A, or if signal B is first sounded signal A is sounded ten seconds after signal B. If the signals are submerged, the chart represents them as separated by a distance of forty-seven thousand one hundred and twenty feet. If the signals were in Vthe air, the distance between them would be eleven thousand feet.

Having thus fully described my invention, I claim and desire to secure by Letters Patent of the United States- 1. A means for enabling sound-signals of sound-signaling devices, arranged in separated relation to each other, to be applied to the fixing of the position of an observer with respect tothe signals, comprising a chart having centers or points corresponding to the location of the signaling devices and intersecting lines arranged with respect to the said centers or points, the location of each line representing an interval of time between two successive signals as heard, whereby the exact situation ot' the observer with relation to said signals may be determined at a glance, substantially as shown and described.

2. A chart forenabling the sou nd-signals of sound-signaling devices, arranged in separated relation to each other, to be applied to the fixing of the position of an observer with respect to the signals, comprisinga chart'having three centers or points corresponding to the arrangement of the signaling devices having intersecting lines arranged with respect to the three centers or points, each line rep- When, however, a sufficient inf resenting an interval of time between two successive signals as heard, whereby an observer can tell at a' glancehis approximate distance from each station, substantially as shown and described.

3. A means forenablingthesound-signals of sound-signaling devices, arranged in sepacation of the signaling devices and intersecting lines arranged with respect to said centers or points substantially as shown and described, which lines bear indicating numbers I5 or characters, representing the time interval between two successive signals as heard.

ARTHUR J. MUNDY Witnesses:.

F. F. RAYMOND, 2d, J. M. DOLAN. 

